The field of the present invention relates devices for positioning cameras, particularly motion picture cameras such as film, videotape or digital cameras. For the purposes of this application motion picture cameras shall refer to any type of moving image recording device including conventional cinema cameras, videotape cameras, digital cameras, CCD cameras, or the like. There have been many devices for supporting and positioning cameras including cranes, tripods, dollies and the like. Combined with any of these camera supports is the tilt head to which the camera is mounted which typically provides for tilting and panning of the camera so as to aim the camera for a given shot. These pan and tilt heads may either be directly controlled manually by hand, e.g. friction heads or geared heads, or remotely via electronic or pneumatic/hydraulic control known as remote heads. In any case, the tilt head typically provides for tilt and panning of the camera.
FIGS. 1 and 2 illustrate a conventional remote head 10 supported by a crane 7. The remote head 10 includes a main support arm 12 and an L-shaped mounting plate 14 on which the camera 5 is mounted. A first motor 16 positioned between the crane 7 and the main support arm 12 provides for panning motion and a second motor 18 mounted between the main support arm 12 and the mounting plate 14 provides for tilting motion. The mounting plate 14 may be rotated so as to point the camera 5 directly vertically downward as shown in FIG. 2 for providing an overhead shot.
In motion picture camera systems, the most well-known geared head is the Panahead(copyright) described in U.S. Pat. No. 4,040,587. A conventional geared head 30 is illustrated in FIG. 3. The device is known as a geared head because the pan and tilt control are operated by rotating hand wheels 40, 42 which drive the pan and tilt mechanisms via drive gears. The geared head 30 includes a base 32 to which a panning mechanism 34 is mounted. The panning mechanism 34 rotates or pans the camera 5 about a vertical axis in a horizontal plane. The tilt mechanism 36/38 mounted on the panning mechanism 34 tilts the camera 5 up and down. The range of motion of the tilt mechanism 36 is limited by the arc of the tilt cradle 38, but may be extended by a separate tilt plate 39 (shown having a female dovetail) mounted on the top of the tilt mechanism 36 permitting the camera 5 which has male dovetail plate 39a attached on the bottom thereof, to be aimed directly upward or downward (i.e. vertical upward as shown in FIG. 3) depending upon which direction the camera is mounted onto the mounting plate 39.
Some heads include a third rotational axis providing for roll of the camera, that is, rotation about an axis positioned generally about the line of sight of the camera lens.
In each of these heads, the positioning mechanisms are interconnected. The tilt mechanism is mounted on the pan mechanism (Pan/Tilt) as in FIGS. 1-3. If a third axis is provided, a roll mechanism may be mounted (a) on the tilt mechanism producing a Pan/Tilt/Roll configuration or (b) on the pan mechanism, the tilt mechanism then being mounted on the roll mechanism producing a Pan/Roll/Tilt configuration.
The present inventor has determined that even providing rotational control about three axes (e.g. Pan/Tilt/Roll), the camera is still limited in the range of motions which it can accomplish.
The present invention is directed to a camera positioning mechanism and positioning method whereby the positioning mechanism is provided with a secondary pan mechanism for rotating the camera about a secondary pan axis, the secondary pan mechanism preferable mounted on the tilt mechanism, the camera then being mounted on the secondary pan mechanism. The secondary pan mechanism may be added to: a PAN/TILT device mounted on the tilt plate; a PAN/TILT/ROLL device mounted on the roll plate; a PAN/ROLL/TILT device mounted on the tilt plate.